Expansible



(No Model.)

G. H. HILL.

EXPANSIBLE BIT.

Patented Mar. 10, 1885.

Unrrnn dra'rhs a'rnnr Garret.

GEORGE II. HILL, OF DERBY, ASSIGNOR OF ONE-HALF TO IVILLIAM .T. W'ELSH,OF BIRMINGHAM, CONNECTICUT.

EXPANSIBLE BIT.

SPECIFICATIQN farming part of Letters Patent No. 313,735, dated March10, 1885.

Application filed January 21, 1585.

T 0 all whom it may concern.-

Be it known that LGEORGE I-I. HILL, a citizen of the United States,residing at Derby, in the countyof Fairfield and State of Connecticut,have invented certain new and useful Improvements in Expansible Bits;and I do hereby declare the following to be afull, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same.

My invention relates to that class of bits which,in addition to theusual spur and cutter of regulation gage, is provided with a detachableand adjustable cutter and spur, so that the ordinary gage of the bit maybe doubled or trebled, or the adjustable cutter may be set at anyintermediate gage.

I-Ieretofore in this class of bits the adjustable cutter has beensecured by means of one or more set-screws. The object of my inventionis to dispense with the use of set-screws and to produce a means oflocking the adjustable cutter in any desired position whichshall beeconomical in cost, easy and quick to adjust, and not liable to get outof order or to wear out. \Vith these ends in view I have devised thesimple and novel means of adjusting and locking the cutter which I willnow describe in connection with the accompanying drawings. forming partof this specification, in which- Figure l is a view of the devicecomplete,thc parts all being in operative position,and showing theadjustable cutter in side elevation. Fig. 2 is a similar view with theadjustable cutter in end elevation. Fig. Sis a view with the adjustablecutter in side elevation, the camlever being turned so as to release thesliding block, and the screw which retains the sliding block beingremoved. Fig. 4 is a rear View of the adjustable cutter detached, andFig. 5 is a rear View of the cam-lever detached.

A represents the shank of the bit, 13 the cutter, G the spur, andD thegimlet, which are of ordinary construction, except that one side of theshank is cut away, as at E, nearly down to the'cutter. Just above thecutter is an un dercut shoulder, E, the plane of which, besidesinclining downward and backward from the front, lies at an angle whichapproximates a right angle to the shank of the hit.

G is the adjustable cutter,which is provided (Yo model.)

with a cutting-edge, G, and a spur,G-. Upon the back of the adjustablecutter is. an undercut shoulder, H, which corresponds exactly withshoulder F upon the bit. The upper edge, I, of the adjustable cutterinclines outward, as shown in Fig. 2. 1

K is a sliding block, which is secured to the shank by a screw, K, whichpasses through slot L,thus leaving the block free to slide. The up peredge, M, of the sliding block is an inward curve, but is not a perfectare, as will be more fully explained. The lower edge, N, isundercut andlies over the upper edge, I, of the adjustable cutter, the planes of thetwo "edges being beveled to correspond.

O is the securing-lever, which is pivoted to the shank by screw 0, andis provided at its lower edge with a curved surface, I, which, however,is not an arc, and which acts as a cam upon the curved upper edge, M, ofthe sliding block, to force the latter down upon the adj ustable cutter,thus locking it in place. \Vhen it is desired to shift the adjustablecutter, the securing-leveris turned off, as in Fig. 3, which leaves thesliding block loose, so that the adjustable cutter may be set at anydesired adjustment.

I preferably make gage-i'narks, as at G, upon the face of the adjustablecutter, so that it may be instantly and accurately adjusted to bore anysized hole within its capacity.

The drawing shows a half-inch bit full size.

If a half-inch hole is desired, the adjustable cutter is of courseremoved. If alarger hole is required, the adjustable cutter isinsertedand locked at the desired adjustment by the cam-lever. In practice ahalf-inch hit may be expanded to borea one-and-one-half-inch hole, or ahole of any intermediate gage; or the adjustment may be changed from onegage to,a11- other without loss of time and without the use of othertools to lock and unlock the adjustable cutter.

In practice I preferably make the sliding block slightly large, andleave it quite loose upon the surface of the shank, as indicated in Fig.2. By this means I am enabled to take up the lost motion should thesliding block and the cam-lever become slightly worn afterlong-continued use.

It will be observed that I have shown the surface of the upper part ofthe cut-away portion of the shank as slightly rounded,as atE Thisrounded portion engages the depression or hollow O in the backvof thecam-lever,thus

- 5 securing the lever in its locking position,there being sufiicientspring in the lever to allow the edgesof the depression to pass over therounded portion E of the shank.

It will of course be understood thatl do not desire to limit myself tothe exact construction which I have shown, as it is evident that thedetails may be varied within reasonable limits without departing fromthe spirit of my inven tion.

I claim 1. The combination,with the bit and an adjustable cutter, of asliding block above the cutter and in contact therewith, and a camadapted to engage the block,whereby'the lat- 20 ter is caused tolock'the adjustable cutter in any desired position.

'2. Abit of ordinary construction having its shank cut away upon oneside, leaving an undercut shoulder, E, and an adjustable cuttertherewith, and an outwardly-inclined upper edge,in combination with asliding block which engages the cutter, and a cam which acts upon theblock to lock the cutter in any desired position.

3. A bit having one side of its shank cut away, substantially as shown,and an underas a cam upon the sliding block, whereby the adjustablecutter is locked in place.

4'. The bit having its shank cut away, as shown, and rounded, as at Eand an adjustable cutter, in combination with a sliding block, and alever whose lower end acts as a cam upon the sliding block, and whoseupper end is provided with a hollow or recess, vO", which engages therounded portion Eflto hold the lever in place.

In testimony whereof I affix my signature in presence of two witnesses.

GEORGE H. HILL. Witnesses:

'WM. J. CLARK, A. F. SHERWOOD.

